fluoroquinolones


Fluoroquinolones

 

Definition

Fluoroquinolones are medicines that kill bacteria or prevent their growth.

Purpose

Fluoroquinolones are antimicrobials, medicines used to treat infections caused by microorganisms. Physicians prescribe these drugs for bacterial infections in many parts of the body. For example, they are used to treat bone and joint infections, skin infections, urinary tract infections, inflammation of the prostate, serious ear infections, bronchitis, pneumonia, tuberculosis, some sexually transmitted diseases (STDs), and some infections that affect people with AIDS.

Description

Fluoroquinolones are available only with a physician's prescription and are sold in tablet and injectable forms. Examples of these medicines are moxifloxacin (Avelox), ciprofloxacin (Cipro), ofloxacin (Floxin), levofloxacin (Levaquin), lomefloxacin (Maxaquin), norfloxacin (Noroxin), enoxacin (Penetrex), gatifloxacin (Tequin), and sparfloxacin (Zagam).In the wake of the anthrax terrorist attacks in the United States in 2001, ciprofloxacin received extensive media attention because it was the only drug labeled as approved by the Food and Drug Administration (FDA) for both prophylaxis and treatment of inhalation anthrax (the most serious form of the disease). However, in late October 2001, the FDA issued a notice clarifying that the antibiotic doxycycline is also approved for anthrax prophylaxis and that doxycycline and amoxicillin are also approved for treatment for all forms of anthrax. The FDA encouraged companies to update labeling of these products with this previously unspecified information.

Recommended dosage

The recommended dosage depends on the type and strength of fluoroquinolone, and the kind of infection for which it is being taken. Check with the physician who prescribed the drug or the pharmacist who filled the prescription for the correct dosage.To make sure the infection clears up completely, take the medicine for as long as it has been prescribed. Do not stop taking the drug just because symptoms begin to improve. Symptoms may return if the drug is stopped too soon.Fluoroquinolones work best when they are at constant levels in the blood. To help keep levels constant, take the medicine in doses spaced evenly through the day and night. Do not miss any doses. For best results, take this medicine with a full glass of water and drink several more glasses throughout the day, every day during treatment with the drug. The extra water will help prevent some side effects. Some fluoroquinolones should be taken on an empty stomach; others may be taken with meals. Check package directions or ask the physician or pharmacist for instructions on how to take the medicine.

Precautions

An important precaution for any antibiotic is that unnecessary use or abuse of antibiotics can encourage drug-resistant strains of bacteria to develop and proliferate. These drug-resistant strains then become difficult, or even impossible, to treat. Bacteria found in hospitals appear to have become especially resilient, and are causing increasing difficulty for patients and the doctors treating them. Following the U.S. 2001 anthrax attacks, for example, the American Medical Association urged its members not to prescribe ciprofloxacin unnecessarily. One fear is that the overuse of the drug could reduce its effectiveness against infections such as typhoid fever, hospital-acquired pneumonia, and others.Research suggests that fluoroquinolones may cause bone development problems in children and teenagers. Infants, children, teenagers, pregnant women, and women who are breastfeeding should not take this medicine unless directed to do so by a physician.Although such side effects are rare, some people have had severe and life-threatening reactions to fluoroquinolones. Call a physician immediately if any of these signs of a dangerous reaction occur:
  • swelling of the face and throat
  • swallowing problems
  • shortness of breath
  • rapid heartbeat
  • tingling of fingers or toes
  • itching or hives
  • loss of consciousness
Some fluoroquinolones may weaken the tendons in the shoulder, hand, or heel, making the tendons more likely to tear. Anyone who notices pain or inflammation in these or other tendon areas should stop taking the medicine immediately and call a physician. Rest and avoid exercise until the physician determines whether the tendons are damaged. If the tendons are torn, surgery may be necessary to repair them.These medicines make some people feel drowsy, dizzy, lightheaded, or less alert. Anyone who takes these drugs should not drive, use machines or do anything else that might be dangerous until they have found out how the drugs affect them.This medicine may increase sensitivity to sunlight. Even brief exposure to sun can cause a severe sunburn or a rash. While being treated with fluoroquinolones, avoid being in direct sunlight, especially between 10 a.m. and 3 p.m.; wear a hat and tightly woven clothing that covers the arms and legs; use a sunscreen with a skin protection factor (SPF) of at least 15; protect the lips with a sun block lipstick; and do not use tanning beds, tanning booths, or sunlamps.Do not take antacids that contain aluminum, calcium, or magnesium at the same time as fluoroquinolones. The antacids may keep the fluoroquinolones from working as they should. If antacids are needed, take them at least two hours before or two hours after taking norfloxacin or ofloxacin, at least four hours before or two hours after taking ciprofloxacin. Follow the same instructions for taking sucralfate (Carafate), a medicine used to treat stomach ulcers and other irritation in the digestive tract and mouth.Anyone who has had unusual reactions to fluoroquinolones or related medicines such as cinoxacin (Cinobac) or nalidixic acid (NegGram) in the past should let his or her physician know before taking the drugs again. The physician should also be told about any allergies to foods, dyes, preservatives, or other substances.Before using fluoroquinolones, people with any of these medical problems should make sure their physicians are aware of their conditions:
  • kidney disease
  • liver disease with kidney disease
  • diseases of the brain or spinal cord, including hardening of the arteries in the brain, epilepsy, and other seizure disorders
Taking fluoroquinolones with certain other drugs may affect the way the drugs work or may increase the chance of side effects.

Side effects

The most common side effects are mild diarrhea, nausea, vomiting, stomach or abdominal pain, dizziness, drowsiness, lightheadedness, nervousness, sleep problems, and headache. These problems usually go away as the body adjusts to the drug and do not require medical treatment unless they are bothersome.More serious side effects are not common, but may occur. If any of the following side effects occur, check with a physician immediately:
  • skin rash or other skin problems such as itching, peeling, hives, or redness
  • fever
  • agitation or confusion
  • hallucinations
  • shakiness or tremors
  • seizures or convulsions
  • tingling of fingers or toes
  • pain where the medicine was injected (lasting after the injection)
  • pain in the calves, spreading to the heels
  • swelling of the calves or lower legs
  • swelling of the face or neck
  • swallowing problems
  • rapid heartbeat
  • shortness of breath
  • loss of consciousness
Other rare side effects may occur. Anyone who has unusual symptoms after taking fluoroquinolones should get in touch with his or her physician.

Interactions

Fluoroquinolones may interact with other medicines. When this happens, the effects of one or both of the drugs may change or the risk of side effects may be greater. Anyone who takes fluoroquinolones should let the physician know all other medicines he or she is taking. Among the drugs that may interact with fluoroquinolones are:
  • antacids that contain aluminum, calcium, or magnesium
  • medicines that contain iron or zinc, including multivitamin and mineral supplements
  • sucralfate (Carafate)
  • caffeine
  • blood thinning drugs such as warfarin (Coumadin)
  • airway opening drugs (bronchodilators) such as aminophylline, theophylline (Theo-Dur and other brands), and oxtriphylline (choledyl and other brands)
  • didanosine (Videx), used to treat HIV infection.
The list above does not include every drug that may interact with fluoroquinolones. Be sure to check with a physician or pharmacist before combining fluoroquinolones with any other prescription or nonprescription (over-the-counter) medicine.

Resources

Other

"Fluoroquinolones (Systemic)." National Library of medicine. 〈http://www.nlm.nih.gov/medlineplus/druginfo/fluoroquinolonessystemic202656.html〉.

Key terms

Bacteria — Tiny, one-celled forms of life that cause many diseases and infections.Bronchitis — Inflammation of the air passages of the lungs.Digestive tract — The stomach, intestines, and other parts of the body through which food passes.Inflammation — Pain, redness, swelling, and heat that usually develop in response to injury or illness.Microorganism — An organism that is too small to be seen with the naked eye.Pneumonia — A disease in which the lungs become inflamed. Pneumonia may be caused by bacteria, viruses, or other organisms, or by physical or chemical irritants.Prostate — A donut-shaped gland in males below the bladder that contributes to the production of semen.Sexually transmitted disease (STD) — A disease that is passed from one person to another through sexual intercourse or other intimate sexual contact.Tendon — A tough band of tissue that connects muscle to bone.Tuberculosis — An infectious disease that usually affects the lungs, but may also affect other parts of the body. Symptoms include fever, weight loss, and coughing up blood.Urinary tract — The passage through which urine flows from the kidneys out of the body.

fluoroquinolones

A family of fluorinated quinolone antibiotics used mainly for the treatment of urinary infections. They include ciprofloxacin and ofloxacin.